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hyphenrf's solution

to Matching Brackets in the OCaml Track

Published at May 06 2020 · 0 comments
Instructions
Test suite
Solution

Given a string containing brackets [], braces {}, parentheses (), or any combination thereof, verify that any and all pairs are matched and nested correctly.

Getting Started

1. For library documentation, follow Useful OCaml resources.

Running Tests

A Makefile is provided with a default target to compile your solution and run the tests. At the command line, type:

make


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Source

Ginna Baker

test.ml

open Base
open OUnit2
open Matching_brackets

let ae exp got _test_ctxt =
assert_equal exp got ~printer:Bool.to_string

let tests = [
"paired square brackets" >::
ae true (are_balanced "[]");
"empty string" >::
ae true (are_balanced "");
"unpaired brackets" >::
ae false (are_balanced "[[");
"wrong ordered brackets" >::
ae false (are_balanced "}{");
"wrong closing bracket" >::
ae false (are_balanced "{]");
"paired with whitespace" >::
ae true (are_balanced "{ }");
"partially paired brackets" >::
ae false (are_balanced "{[])");
"simple nested brackets" >::
ae true (are_balanced "{[]}");
"several paired brackets" >::
ae true (are_balanced "{}[]");
"paired and nested brackets" >::
ae true (are_balanced "([{}({}[])])");
"unopened closing brackets" >::
ae false (are_balanced "{[)][]}");
"unpaired and nested brackets" >::
ae false (are_balanced "([{])");
"paired and wrong nested brackets" >::
ae false (are_balanced "[({]})");
"paired and incomplete brackets" >::
ae false (are_balanced "{}[");
"too many closing brackets" >::
ae false (are_balanced "[]]");
"math expression" >::
ae true (are_balanced "(((185 + 223.85) * 15) - 543)/2");
"complex latex expression" >::
ae true (are_balanced "\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2 \\end{array}\\right)");
]

let () =
run_test_tt_main ("matching-brackets tests" >::: tests)
let are_balanced s =
let bracks = Stack.create() in
let compare s c = assert ((Stack.pop s) = c) in
let parse = function
|'(' |'{' |'[' as o -> Stack.push o bracks
|')' -> compare bracks '('
|'}' -> compare bracks '{'
|']' -> compare bracks '['
| _ -> ()
in try
String.iter (fun c -> parse c) s;
if Stack.is_empty bracks then true
else false
with _ ->
false